Field of the Invention
The invention relates to a device for safeguarding hazardous locations of a printing unit on rotary printing presses, particularly with multi-partite protective coverings having an areal or sheetlike form.
A protective device on counter-rotating cylinders, particularly in printing presses, has become known heretofore from German Patent 19 18 173. A protective rod disposed parallel to axes of cylinders, which are changeable in the positions thereof relative to one another, automatically follows a swivelling movement of the cylinders and is swivellably mounted parallel to the counter-rotating cylinders and at a constantly like spaced distance therefrom. This heretofore known protective device, however, merely safeguards the printing nip between two printing-unit cylinders.
German Published Non-Prosecuted Patent Application (DE-OS) 29 14 152 discloses a safety device on sheet-fed rotary printing presses for safeguarding a roller nip, particularly between an impression cylinder and a blanket cylinder. Two metal plates or sheets carried on a hinge are in contact with a limit switch through the intermediary of a double-armed lever. The entire safety device of this German application, if required, can be exchanged for a complete washing device. Furthermore, the safety device can also be used for sheet guidance. A disadvantage, however, is that, with this heretofore known safety device, it is not possible to effect a complete safeguarding of all hazardous locations of a printing unit.
In German Published Patent Document 81 11 567 U1, a protective device on rotary printing presses is described wherein protective coverings, in an outwardly swung condition, are swivelled into engagement with one another, the individual protective coverings forming limit stops for protective coverings adjacent thereto. In this manner, good accessibility and very large operator zones on the printing unit are able to be achieved. A disadvantage of this heretofore known device, however, is that the protective coverings are manually operatable, so that the pressmen are able to open them before the printing press has come to a complete stop.
It is accordingly an object of the invention, starting from the aforedescribed state of the prior art, to provide a device for safeguarding hazardous locations on a printing unit independently of the pressman or other operating personnel.